Unless otherwise indicated herein, the description in this section is not prior art to the claims in this application and is not admitted to be prior art by inclusion in this section.
An image forming apparatus performs to develop a latent image formed on an image carrier, which is constituted of such as a photoreceptor, with a developing device to visualize the latent image as a toner image. The developing device houses a developer including toner in a developing container, includes a developing roller supplying the image carrier with developer, and includes a stir conveying member supplying the developing roller with the developer housed in the developing container with stirring and conveying the developer.
For ensuring a satisfactory image quality, a space between an outer peripheral surface of the developing roller and an outer peripheral surface of a photoreceptor drum (development gap) should be held with high accuracy. In view of this, an image forming apparatus including a developing pulley located at both ends of a rotation shaft of the developing roller and a pressing member located to press the developing roller to the photoreceptor drum is widely employed. In this image forming apparatus, the developing pulley is in contact with the outer peripheral surface of the photoreceptor drum and is rotationally driven with respect to the photoreceptor drum. This ensures the developing roller to rotate with respect to the photoreceptor drum in a state keeping a predetermined development gap.
A typical developing device employs a configuration including a development drive unit to rotatably drive the developing roller in the developing device and transmitting a rotary drive power from the developing device main body side to the development drive unit via a gear. Alternatively, it is also employed that a configuration including a replenishment drive unit to rotatably drive a toner replenishment screw of a toner replenishment container in the developing device and transmitting a rotary drive power from the developing device main body side to the replenishment drive unit via a gear.
An image forming apparatus transmitting a rotary drive power to a developing roller via a gear has been proposed.